Fluid pressure brake system

ABSTRACT

A tractor-trailer brake system having spring-applied, fluid pressure-released, emergency-parking brake actuators wherein a separate fluid pressure reservoir on the tractor may be communicated to the actuators to release the brakes and a separate tank on the trailer is automatically communicated to the trailer actuators to release the same through electrical means responsive to release of the tractor brake. The separate trailer tank may be communicated manually with the trailer brakes when the tractor and trailer are disconnected.

United States Patent Campanini [54] FLUID PRESSURE BRAKE SYSTEM [72]Inventor: Sergio Campanini, Lincolnwood, Ill.

[73] Assignee: Berg Mfg. & Sales Co., Des Plaines,

Ill.

[22] Filed: Jan. 13, 1971 [21] Appl. No.: 106,154

[52] US. Cl ....303/9 [51] Int. Cl. ..B60t 13/22 [58] Field of Search..303/7, 9; 188/3 [56] References Cited UNITED STATES PATENTS 3,073,623l/1963 Owen ..l88/3 R X 3,237,995 3/1966 Dobrikin ..303/9 [451 Sept. 19,1972 FOREIGN PATENTS OR APPLICATIONS 1,178,646 1/1970 Great Britain..303/7 Primary Examiner-Edward A. Sroka Attorney-Parker, Carter &Markey 5 7] ABSTRACT A tractor-trailer brake system havingspring-applied, fluid pressure-released, emergency-parking brakeactuators wherein a separate fluid pressure reservoir on the tractor maybe communicated to the actuators to release the brakes and a separatetank on the trailer is automatically communicated to the traileractuators to release the same through electrical means responsive torelease of the tractor brake. The separate trailer tank may becommunicated manually with the trailer brakes when the tractor andtrailer are disconnected.

7 Claims, 3 Drawing Figures FLUID PRESSURE BRAKE SYSTEM SUMMARY OF THEINVENTION This invention relates to fluid pressure brake systems fortractor-trailer vehicles and the like.

One purpose of the invention is to provide means for substantiallysimultaneously releasing spring-applied trailer brakes in automaticresponse to manual release of tractor brakes.

Another purpose is to provide means for manually releasingspring-applied trailer brakes when no tractor is connected to thetrailer.

Another purpose is to provide a tractor-trailer brake system havingalternate means for releasing spring-applied brakes.

Another purpose is to provide a tractor-trailer fluid pressure brakesystem having a first means for releasing spring-applied brakes and asecond, independent means for releasing said brakes.

Other purposes may appear from time to time during the course of thespecification and claims.

BRIEF DESCRIPTION OF THE DISCLOSURE The invention is illustrated more orless diagrammatically in the accompanying drawings, wherein:

FIG. 1 is a schematic illustration of a tractor brake system of theinvention;

FIG. 2 is a schematic illustration of a trailer brake system of theinvention; and

FIG. 3 is a view in partial cross section and on an enlarged scale of avalve of the invention.

Like parts are indicated by like numerals throughout the specificationand drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,and particularly to FIG. 1, the numeral 1 designates a fluid pressurereservoir or tank. It will be understood that the reservoir 1 may takethe form of one or more tanks, the single tank 1 being illustrated forclarity. A separate or protected fluid pressure reservoir 2 is suppliedwith fluid pressure through the conduit 3 from tank 1, the check valve 4precluding flow of fluid pressure from tank 2 back to tank 1.

A service conduit 5 communicates tank 1 with valve 6 when the footpedal-operated brake application valve 7 in conduit 5 is actuated by thevehicle operator. Fluid pressure delivered to valve 6 is communicated byconduits 8 with the service side of the tractor brake actua tors 9, asis well known in the art. While two actuators are shown in the drawings,the number may vary. In this regard it will be understood that theschematic illustrations in FIGS. 1 and 2 are limited to parts necessaryfor an understanding of the invention and for clarity.

An emergency fluid pressure conduit 10 communicates tank 1, whenmanually operable valve 11 is opened, with a two-way check valve 12.Conduit l3 communicates check valve 12 with the emergency sides ofactuators 9 to compress the emergency brakeactuating springs therein andthus to hold the springapplied, brake-actuating elements of actuators 9in released position. The actuators 9 are of standard, well knownconstruction having service and emergency chambers therein, as shown forexample in US. Letters Pat. No. 3,131,609. Conduit 10 includes a branch10a leading to the emergency gladhand connector 14 on the tractor. Aservice pressure conduit 15 communicates tank I with the servicegladhand connector 16 when valve 7 is actuated.

A fluid pressure conduit 20 communicates tank 2 with the opposite inletof two-way check valve 12 when manually operable valve 21 is opened. Itwill be understood that fluid pressure delivered to either inlet ofvalve 12 will be delivered through conduit 13 to the emergency chambersof actuators 9 to release the springs therein, superior pressureintroduced at either inlet of valve 12 being effective to close theopposite inlet. Conduit 20 also delivers fluid pressure from tank 2,when valve 21 is opened, to a normally-open, pneumatically operatedswitch 22 to close the same and to deliver electrical energy throughconductor 23 to connector 24.

Referring now to FIG. 2, a service fluid pressure reservoir or tank 30provides fluid pressure through conduit 31 to a separate or protected"tank 32, the check valve 33 precluding redirection of fluid pressurefrom tank 32 to tank 30. The valve 33 permits a flow only above apredetermined fluid pressure level of, for example, 45 pounds.

Tank 30 also delivers fluid pressure to relay valve 34 of conventionalconstruction, through conduit 35. Service gladhand connector 36 isprovided for connection with gladhand l6 and delivers fluid pressurethrough conduit 37 to valve 34. Conduits 38 deliver fluid pressure fromvalve 34 to actuators 39, it being understood that actuators 39correspond to actuators 9 illustrated in FIG. 1.

Emergency gladhand connector 40 is provided for connection with gladhand14 of the tractor for delivery of fluid pressure through conduit 41 totwo-way check valve 42. A branch conduit 41a delivers fluid pressurethrough one-way check valve 43 to tank 30. Conduit 44 communicates theoutlet of two-way check valve 42 with the emergency chambers ofactuators 39 to compress and release the springs therein.

A conduit 50 communicates tank 32 with the opposite inlet of check valve42 when the three-way electropneumatic valve 51 is in one position. Aconnector 52 is provided on the trailer for connection with connector 24of the tractor and conductor 53 delivers electrical energy to valve 51to move the same to said position for delivery of fluid pressure fromtank 32 through valve 42 and conduit 44 to the emergency chambers ofactuators 39. Valve 51 includes a manually accessible handle element 54for manual movement of valve 51 into said position when the trailer isdisconnected from the tractor.

Referring now to FIG. 3, the valve 51 is shown to include a housing 60having an inlet 61, an outlet 62 and an exhaust outlet 63. The elements61, 62, 63 communicate with a valve chamber 64. A valve shuttle 65 has afirst valve face 66 yieldingly urged toward a fixed valve seat 67between inlet 61 and outlet 62 and a second valve face 68 positioned forcontact by movable valve face 69 yieldingly urged away from face 68. Itwill be observed that annular valve faces 66, 68 are formed on a singlevalve face member of compressible or rubberlike material and liecoaxially in a single plane, the face 68 being of lesser diameter thanthe face 66.

Movable valve element 69 includes a stem 70 rising, as the parts areshown, into a solenoid chamber 71 with which the conductor 53 isconnected, handle 54 extending from chamber 71 for manual movement ofztgm 70 and the shuttle-operating valve seat element The use andoperation of the invention are as follows:

In normal operation the vehicle operator activates the actuators 9, 39by means of brake-application valve 7, delivering service fluid pressureto the service chambers of actuators 9, 39 to apply the tractor andtrailer brakes. Fluid pressure is normally continuously maintained inthe emergency chambers of actuators 9 from tank 1 through normally-openvalve 11, check valve 12 and conduit 13. Similarly, fluid pressure isnormally maintained in the emergency chambers of actuators 39 throughconduit 10, connectors 14, 40, conduit 41, valve 42 and conduit 44.Should the vehicle operator wish to employ the springs in actuators 9,39 to apply the brakes, in an emergency or for parking, the operatormoves the valve 11 to its exhaust position, thus withdrawing fluidpressure from the emergency chambers in actuators 9, 39 and freeing thesprings therein to apply the brakes. Similarly, in the event of a lossof pressure, the fluid pressure in said emergency chambers would beexhausted, producing an automatic application of emergency brakes by thesprings in actuators 9, 39.

With the brakes applied and held in brakes-on position by the springs inactuators 9, 39, situations may occur in which normal fluid pressure isnot available for release of said brakes. In the event of an automaticor manual emergency operation, for example, it may be necessary to movethe vehicle out of traffic before the loss of normal pressure can berectified. In such event, the operator is provided with protected tank2, not effected by such loss of normal pressure, and the valve 21.Operation of valve 21 delivers fluid pressure from tank 2 throughtwo-way check valve 12 and conduit 13 to the emergency chambers ofactuators 9 to retract the springs therein and free the tractor brakesfor vehicle operation. Substantially simultaneously, in response tofluid pressure in conduit 20, switch 22 is closed to deliver electricalenergy through conductor 23, connectors 24, 52 and conductor 53 toactuate valve 51. Delivery of electrical energy to the solenoid orelectrically operated element 71 produces a downward movement, as theparts are shown, of valve-actuating face 69 to close the exhaust port 63and to move valve seat 66 off its seat, thus communicating inlet 61 withoutlet 62 and delivering fluid pressure from trailer protected tank 32through conduit 50, valve 42 and conduit 44 to the emergency chambers ofactuators 39 to release the spring-applied brakes of the trailer.

Should the operator thereafter wish to again utilize the springs ofactuators 9, 39 to apply the brakes, it is only necessary that theoperator move valve 21 to its exhaust position. Thereupon the switch 22will open, electrical energy will be no longer available to valve 51,and the spring engaging face 69 will move the same to the position shownin FIG. 3, thus exhausting the spring chambers of actuators 39 andclosing inlet 61 against loss of fluid pressure from tank 32.

When the trailer is disconnected from a tractor, as for example when thetrailer is in a yard, the springs of actuators 39 will be in brakes-onor parked position. Should the operator wish to move the trailer,without fully connecting a tractor, handle 54 may be manually operatedto open valve 51 and to supply pressure from tank 32 to actuators 39 torelease the springs therein, as above described. When the trailer hasbeen repositioned and the operator wishes to again apply the parkingbrakes, the handle 54 is simply released out to return the valve 51 tothe position shown, for example, in FIG. 3.

While valve 51 is shown as alternatively operable by manual andelectrical means and a suitable detent (not shown) could be provided tohold handle 54 in its inward position, it will be understood that valve51 could be solely an electrically operated valve and a separate, solelymanually operated valve, with associated conduits communicating it withtank 32 and valve 42, could be provided without departing from thenature and scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In a tractor-trailer fluid pressure brake system, a first fluidpressure reservoir on the tractor, a second fluid pressure reservoir onthe tractor, means delivering fluid pressure from said first to saidsecondreservoir and precluding delivery of fluid pressure from saidsecond to said first reservoir, spring-applied, fluid pressure releasedbrake actuators on said tractor, a conduit communicating said secondreservoir with said actuators, a manually operable valve controllingsaid communication, a fluid pressure-actuated electrical switch on saidtractor and connected to said conduit for simultaneous delivery of fluidpressure to said actuators and said switch, an electrical conductorconnected to said switch, a third fluid pressure reservoir mounted onsaid trailer, a fourth fluid pressure reservoir mounted on said trailer,means delivering fluid pressure from said third to said fourth fluidpressure reservoir and precluding delivery of fluid pressure from saidfourth to said third reservoir, spring-applied, fluid pressure brakeactuators on said trailer, a conduit communicating said fourth reservoirwith said trailer actuators, an electrically operated valve controllingsaid last-named communication, said conductor being connected to saidlast-named valve, said last-named valve being movable into a firstposition communicating said fourth reservoir with said trailer actuatorsin response to delivery of fluid pressure to said switch andautomatically yieldably urged into a second position exhausting saidtrailer actuators to atmosphere in the absence of electrical energydelivered by said conductor.

2. The structure of claim 1, characterized by and including means formanually moving said last-named valve into said first position.

3. A tractor-trailer vehicle brake system including spring-applied,fluid pressure released brake actuators on the tractor and on thetrailer, a first pair of fluid pressure reservoirs on the tractor, asecond pair of fluid pressure reservoirs on the trailer and valve andconduit means selectably, alternately connecting one of said firstreservoirs with said tractor actuators and one of said second reservoirswith said trailer actuators.

4. The structure of claim 3, wherein a tractormounted, manuallysoperablevalve connects one of said reservoirs on said tractor with saidactuators on said tractor and simultaneously operates a switchelectrically connected to an electrically operable valve on saidtrailer, said electrically operated valve controlling communicationbetween one of said reservoirs on said trailer with said actuators onsaid trailer. v

5. In a tractor-trailer vehicle brake system, spring-applied fluidpressure-released brake actuators on the tractor and on the trailer,first and second fluid pressure sources on the tractor and on thetrailer, first valve and conduit means communicating said first sourceswith their associated actuators, second valve and conduit meanscommunicating said second sources with

1. In a tractor-trailer fluid pressure brake system, a first fluidpressure reservoir on the tractor, a second fluid pressure reservoir onthe tractor, means delivering fluid pressure from said first to saidsecond reservoir and precluding delivery of fluid pressure from saidsecond tO said first reservoir, springapplied, fluid pressure releasedbrake actuators on said tractor, a conduit communicating said secondreservoir with said actuators, a manually operable valve controllingsaid communication, a fluid pressure-actuated electrical switch on saidtractor and connected to said conduit for simultaneous delivery of fluidpressure to said actuators and said switch, an electrical conductorconnected to said switch, a third fluid pressure reservoir mounted onsaid trailer, a fourth fluid pressure reservoir mounted on said trailer,means delivering fluid pressure from said third to said fourth fluidpressure reservoir and precluding delivery of fluid pressure from saidfourth to said third reservoir, spring-applied, fluid pressure brakeactuators on said trailer, a conduit communicating said fourth reservoirwith said trailer actuators, an electrically operated valve controllingsaid last-named communication, said conductor being connected to saidlast-named valve, said lastnamed valve being movable into a firstposition communicating said fourth reservoir with said trailer actuatorsin response to delivery of fluid pressure to said switch andautomatically yieldably urged into a second position exhausting saidtrailer actuators to atmosphere in the absence of electrical energydelivered by said conductor.
 2. The structure of claim 1, characterizedby and including means for manually moving said last-named valve intosaid first position.
 3. A tractor-trailer vehicle brake system includingspring-applied, fluid pressure released brake actuators on the tractorand on the trailer, a first pair of fluid pressure reservoirs on thetractor, a second pair of fluid pressure reservoirs on the trailer andvalve and conduit means selectably, alternately connecting one of saidfirst reservoirs with said tractor actuators and one of said secondreservoirs with said trailer actuators.
 4. The structure of claim 3,wherein a tractor-mounted, manually-operable valve connects one of saidreservoirs on said tractor with said actuators on said tractor andsimultaneously operates a switch electrically connected to anelectrically operable valve on said trailer, said electrically operatedvalve controlling communication between one of said reservoirs on saidtrailer with said actuators on said trailer.
 5. In a tractor-trailervehicle brake system, spring-applied fluid pressure-released brakeactuators on the tractor and on the trailer, first and second fluidpressure sources on the tractor and on the trailer, first valve andconduit means communicating said first sources with their associatedactuators, second valve and conduit means communicating said secondsources with their associated actuators, said second valve on thetrailer being automatically opened to communicate the second trailersource with the trailer actuators in response to manual opening of thesecond valve on the tractor to communicate the second tractor sourcewith the tractor actuators.
 6. The structure of claim 5, characterizedby and including manually operable means communicating said secondtrailer source with the trailer actuators independently of the tractor.7. The The structure of claim 5, characterized by and including manuallyoperable means for opening said second valve on the trailer.